Thought I’d share this with the group because it’s incredibly handy for making some minor fixes to a print. I just printed a Raspberry pi case and the screw holes were a little small.
I’ve used this reaming tool for years that the RC folks use to make mounting holes in RC car bodies. Definitely something you should have in your tool box.
definitely one of my favorite and most useful. Here is the style I like (make sure you don’t carry in your laptop bag if flying 
https://www.amazon.com/ShareGoo-Aluminum-Expanding-Connector-Protective/dp/B074WC52Q1/ref=sr_1_2?s=toys-and-games&ie=UTF8&qid=1527096659&sr=1-2&keywords=reamer
http://a.co/gl18oVa
straight into my ebay basket 
@Cristian_Nicola ditto! Thanks for the tip @Tim_Sills
Glad to help. Everyone’s printers are slightly different so half a mm here or there can be a PIA when doing the assembly.
The Step Drill is the better tool to use because it leaves a non tapered hole.
https://m.dhgate.com/product/titanium-step-drill-bit-set-hex-shank-28/410749073.html#pd-019
https://m.dhgate.com/product/titanium-step-drill-bit-set-hex-shank-28/410749073.html#pd-019
@MidnightVisions If only those weren’t imperial. Nobody in 3D printing uses anything other than Metric. (thankfully)
Yeah, it is still very handy no matter what anyone else says (to me). Nothing like whipping out an electric drill and battery out of my laptop case (I carry the reamer with me everywhere).
@ThantiK AliExpress has metric step drills. The spiral ones tend to do a better job.
@ThantiK Metric or imperial doesn’t matter, its the better tool, and just an example picture anyway
How to get it!?
@Nagabhushana_Rao_N Your local industrial supply company or tool shop should carry them.
@MidnightVisions harbor freight carries these in the U.S they may work good on plastics but are crap for metal projects they become dull after one or two holes.
@MidnightVisions Is there a handheld version of the step drill?
@Joe_Duong No, just use a file handle.
Search the usual sources for an adjustable reamer set
Mlm mo L and p Lpokki
@Joe_Duong I use my largest tap handle and it works perfect.
